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qemu / qemu / e1f7b4812eab992de46c98b3726745afb042a7f0
commite1f7b4812eab992de46c98b3726745afb042a7f0[log] [tgz]
authorMichael S. Tsirkin <mst@redhat.com>Fri Nov 30 00:02:56 2012 +0200
committerAnthony Liguori <aliguori@us.ibm.com>Thu Nov 29 17:25:02 2012 -0600
tree288ec43f0807224674026579208dc46748bcaf32
parent044d003db9b6a588be2c9d0ec9de694ba3848551 [diff]
virtio: limit avail bytes lookahead

Commit 0d8d7690850eb0cf2b2b60933cf47669a6b6f18f introduced
a regression in virtio-net performance because it looks
into the ring aggressively while we really only care
about a single packet worth of buffers.
Reported as bugzilla 1066055 in launchpad.

To fix, add parameters limiting lookahead, and
use in virtqueue_avail_bytes.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: Edivaldo de Araujo Pereira <edivaldoapereira@yahoo.com.br>
Tested-by: Edivaldo de Araujo Pereira <edivaldoapereira@yahoo.com.br>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
4 files changed
tree: 288ec43f0807224674026579208dc46748bcaf32
  1. audio/
  2. backends/
  3. block/
  4. bsd-user/
  5. default-configs/
  6. docs/
  7. fpu/
  8. fsdev/
  9. gdb-xml/
  10. hw/
  11. include/
  12. libcacard/
  13. linux-headers/
  14. linux-user/
  15. net/
  16. pc-bios/
  17. qapi/
  18. qga/
  19. QMP/
  20. qom/
  21. roms/
  22. scripts/
  23. slirp/
  24. stubs/
  25. sysconfigs/
  26. target-alpha/
  27. target-arm/
  28. target-cris/
  29. target-i386/
  30. target-lm32/
  31. target-m68k/
  32. target-microblaze/
  33. target-mips/
  34. target-openrisc/
  35. target-ppc/
  36. target-s390x/
  37. target-sh4/
  38. target-sparc/
  39. target-unicore32/
  40. target-xtensa/
  41. tcg/
  42. tests/
  43. trace/
  44. ui/
  45. pixman
  46. .exrc
  47. .gitignore
  48. .gitmodules
  49. .mailmap
  50. a.out.h
  51. acl.c
  52. acl.h
  53. aes.c
  54. aes.h
  55. aio-posix.c
  56. aio-win32.c
  57. alpha-dis.c
  58. alpha.ld
  59. arch_init.c
  60. arch_init.h
  61. arm-dis.c
  62. arm.ld
  63. async.c
  64. balloon.c
  65. balloon.h
  66. bitmap.c
  67. bitmap.h
  68. bitops.c
  69. bitops.h
  70. block-migration.c
  71. block-migration.h
  72. block.c
  73. block.h
  74. block_int.h
  75. blockdev-nbd.c
  76. blockdev.c
  77. blockdev.h
  78. blockjob.c
  79. blockjob.h
  80. bswap.h
  81. bt-host.c
  82. bt-host.h
  83. bt-vhci.c
  84. buffered_file.c
  85. buffered_file.h
  86. cache-utils.c
  87. cache-utils.h
  88. Changelog
  89. cmd.c
  90. cmd.h
  91. CODING_STYLE
  92. compatfd.c
  93. compatfd.h
  94. compiler.h
  95. config.h
  96. configure
  97. console.c
  98. console.h
  99. COPYING
  100. COPYING.LIB
  101. coroutine-gthread.c
  102. coroutine-sigaltstack.c
  103. coroutine-ucontext.c
  104. coroutine-win32.c
  105. cpu-all.h
  106. cpu-common.h
  107. cpu-defs.h
  108. cpu-exec.c
  109. cpus.c
  110. cpus.h
  111. cputlb.c
  112. cputlb.h
  113. cris-dis.c
  114. cursor.c
  115. cursor_hidden.xpm
  116. cursor_left_ptr.xpm
  117. cutils.c
  118. def-helper.h
  119. device_tree.c
  120. device_tree.h
  121. dis-asm.h
  122. disas.c
  123. disas.h
  124. dma-helpers.c
  125. dma.h
  126. dump-stub.c
  127. dump.c
  128. dump.h
  129. elf.h
  130. envlist.c
  131. envlist.h
  132. error.c
  133. error.h
  134. event_notifier-posix.c
  135. event_notifier-win32.c
  136. event_notifier.h
  137. exec-all.h
  138. exec-memory.h
  139. exec.c
  140. gdbstub.c
  141. gdbstub.h
  142. gen-icount.h
  143. HACKING
  144. hmp-commands.hx
  145. hmp.c
  146. hmp.h
  147. host-utils.c
  148. host-utils.h
  149. hppa-dis.c
  150. hppa.ld
  151. hwaddr.h
  152. i386-dis.c
  153. i386.ld
  154. ia64-dis.c
  155. ia64.ld
  156. input.c
  157. int128.h
  158. iohandler.c
  159. ioport.c
  160. ioport.h
  161. iorange.h
  162. iov.c
  163. iov.h
  164. json-lexer.c
  165. json-lexer.h
  166. json-parser.c
  167. json-parser.h
  168. json-streamer.c
  169. json-streamer.h
  170. kvm-all.c
  171. kvm-stub.c
  172. kvm.h
  173. libfdt_env.h
  174. LICENSE
  175. lm32-dis.c
  176. m68k-dis.c
  177. m68k.ld
  178. main-loop.c
  179. main-loop.h
  180. MAINTAINERS
  181. Makefile
  182. Makefile.dis
  183. Makefile.objs
  184. Makefile.target
  185. Makefile.user
  186. memory-internal.h
  187. memory.c
  188. memory.h
  189. memory_mapping-stub.c
  190. memory_mapping.c
  191. memory_mapping.h
  192. microblaze-dis.c
  193. migration-exec.c
  194. migration-fd.c
  195. migration-tcp.c
  196. migration-unix.c
  197. migration.c
  198. migration.h
  199. mips-dis.c
  200. mips.ld
  201. module.c
  202. module.h
  203. monitor.c
  204. monitor.h
  205. nbd.c
  206. nbd.h
  207. net.c
  208. net.h
  209. notify.c
  210. notify.h
  211. os-posix.c
  212. os-win32.c
  213. osdep.c
  214. osdep.h
  215. oslib-posix.c
  216. oslib-win32.c
  217. page_cache.c
  218. path.c
  219. pci-ids.txt
  220. poison.h
  221. ppc-dis.c
  222. ppc.ld
  223. ppc64.ld
  224. qapi-schema-guest.json
  225. qapi-schema-test.json
  226. qapi-schema.json
  227. qbool.c
  228. qbool.h
  229. qdict-test-data.txt
  230. qdict.c
  231. qdict.h
  232. qemu-aio.h
  233. qemu-barrier.h
  234. qemu-bridge-helper.c
  235. qemu-char.c
  236. qemu-char.h
  237. qemu-common.h
  238. qemu-config.c
  239. qemu-config.h
  240. qemu-coroutine-int.h
  241. qemu-coroutine-io.c
  242. qemu-coroutine-lock.c
  243. qemu-coroutine-sleep.c
  244. qemu-coroutine.c
  245. qemu-coroutine.h
  246. qemu-doc.texi
  247. qemu-error.c
  248. qemu-error.h
  249. qemu-file.h
  250. qemu-ga.c
  251. qemu-img-cmds.hx
  252. qemu-img.c
  253. qemu-img.texi
  254. qemu-io.c
  255. qemu-lock.h
  256. qemu-log.c
  257. qemu-log.h
  258. qemu-nbd.c
  259. qemu-nbd.texi
  260. qemu-objects.h
  261. qemu-option-internal.h
  262. qemu-option.c
  263. qemu-option.h
  264. qemu-options-wrapper.h
  265. qemu-options.h
  266. qemu-options.hx
  267. qemu-os-posix.h
  268. qemu-os-win32.h
  269. qemu-pixman.c
  270. qemu-pixman.h
  271. qemu-progress.c
  272. qemu-queue.h
  273. qemu-seccomp.c
  274. qemu-seccomp.h
  275. qemu-sockets.c
  276. qemu-tech.texi
  277. qemu-thread-posix.c
  278. qemu-thread-posix.h
  279. qemu-thread-win32.c
  280. qemu-thread-win32.h
  281. qemu-thread.h
  282. qemu-timer-common.c
  283. qemu-timer.c
  284. qemu-timer.h
  285. qemu-tls.h
  286. qemu-tool.c
  287. qemu-user.c
  288. qemu-x509.h
  289. qemu-xattr.h
  290. qemu.sasl
  291. qemu_socket.h
  292. qerror.c
  293. qerror.h
  294. qfloat.c
  295. qfloat.h
  296. qint.c
  297. qint.h
  298. qjson.c
  299. qjson.h
  300. qlist.c
  301. qlist.h
  302. qmp-commands.hx
  303. qmp.c
  304. qobject.h
  305. qstring.c
  306. qstring.h
  307. qtest.c
  308. qtest.h
  309. range.h
  310. readline.c
  311. readline.h
  312. README
  313. rules.mak
  314. s390-dis.c
  315. s390.ld
  316. savevm.c
  317. sh4-dis.c
  318. softmmu-semi.h
  319. softmmu_defs.h
  320. softmmu_exec.h
  321. softmmu_header.h
  322. softmmu_template.h
  323. sparc-dis.c
  324. sparc.ld
  325. sparc64.ld
  326. spice-qemu-char.c
  327. sysemu.h
  328. tcg-runtime.c
  329. tci-dis.c
  330. tci.c
  331. thread-pool.c
  332. thread-pool.h
  333. thunk.c
  334. thunk.h
  335. TODO
  336. trace-events
  337. translate-all.c
  338. uboot_image.h
  339. uri.c
  340. uri.h
  341. user-exec.c
  342. VERSION
  343. version.rc
  344. vgafont.h
  345. vl.c
  346. vmstate.h
  347. x86_64.ld
  348. xen-all.c
  349. xen-mapcache.c
  350. xen-mapcache.h
  351. xen-stub.c